A Mobile Number Portability (MNP) is a capability provided for users by a network, which enables a mobile user to change his/her subscribed network without changing his/her Mobile Station International Integrated Services Digital Network Number (MSISDN).
The most internationally popular MNP solution is a Signaling Relay Function for support of MNP (MNP-SRF) provided by the European Telecommunication Standard Institute (ETSI) for the signal relay mode of Global System for Mobile communications (GSM) systems. According to the technical solution in accordance with embodiments of the present invention is that: setting an MNP-SRF module in a GSM signaling network and configuring data on switches or other devices associated with the MNP in the GSM signaling network. Thus, when a key Mobile Application Part (MAP) message carrying an E.164 number passes the MNP-SRF module, the MNP-SRF module can inquire about the Number Portability NP) state of the MSISDN from a Number Portability Database (NPDB), and then perform appropriate subsequent processing according to the NP state. FIG. 1 is a schematic diagram illustrating the location of the MNP-SRF module in a network and interaction between the MNP-SRF module and other network entities. As shown in FIG. 1, the MNP-SRF module is located on a Signal Transfer Point (STP).
FIG. 2 is a schematic diagram illustrating a message flow for processing a Mobile Originated (MO) message according to the prior art, the detailed steps are as follows.
Steps 201˜202, a Mobile Station (MS) submits an SM and address information of a Short Message Serving Center (SMSC) to its serving-Mobile Switching Center (MSC), then the MSC requests the subscription data of the MS from a Visited Location Register (VLR) via the MO SM Transfer message.
The address information of the SMSC is stored in a Subscriber Identity Module (SIM) of the MS. When the MS cancels a subscription from one network and subscribes to another, the address information of the SMSC needs to be modified manually, i.e., the address information of the SMSC stored in the SIM needs to be modified from the network to which the subscription has been canceled to the newly subscribed one.
When the MS moves to a certain region, a Home Location Register (HLR) corresponding to the MS will send the subscription data of the MS to the serving-VLR of the MS, and the subscription data includes the mobile number of the MS.
Steps 203˜207, the VLR returns subscription data of the MS to the MSC, and the MSC sends to the SMSC the mobile number of the MS, i.e., the calling party number, together with the SM. The SMSC determines whether the MS is a subscriber of its own according to the calling party number. If the MS is a subscriber of the SMSC, the SMSC determines that the SM passes calling party authentication and sends the SM to the called party. If the MS is not a subscriber of the SMSC, the SMSC determines that the SM fails in calling party authentication and discards the SM.
It can be seen from the process shown in FIG. 2 that, after an MS cancels a subscription from a network A and a mobile number, such as the MSISDN, is carried to a newly subscribed network B, if the MS still reserves the address information of the SMSC of network A, there may be problems as follows.
The SMSC generally authenticates an MS according to a number segment that a mobile number belongs to, if the signaling network of network A and that of network B are inter-working networks, the MS subscribing to network B can still pass the authentication of the SMSC in network A to which the MS has canceled the subscription. Therefore, the MS can freely use services and resources provided by the SMSC of network A to send SM, and meanwhile, the MS cannot send SM via the SMSC of newly subscribed network B since the MS cannot pass the authentication of the SMSC of newly subscribed network B. This obviously results in an unreasonable utilization of SM serving resources. For example, after a mobile number de-subscribing from network A of China Mobile in Shenzhen, it subscribes to network B of China Mobile in Beijing. Since the signaling networks of networks A and B are inter-working networks, the MS will still use the SMSC of network A to send SM if the MS reserves the address information of the SMSC of network A, and the MS cannot send SM via the SMSC of network B since it cannot pass the authentication of the SMSC of network B.
If the signaling networks of network A and network B are not inter-working networks, the MS keeping the address information of the SMSC of network A to which the subscription has been canceled will be unable to use a Short Message Service (SMS). For example, since the signaling networks of China Mobile and China Unicom are not inter-working networks, if a mobile number cancels the subscription from one of the signaling networks, network A, and subscribes to the other network, network B, the MS will not be able to use the SMS. The reason is that the SM originated by the MS, i.e. the MO SM, cannot penetrate the newly subscribed signaling network B to reach the SMSC located in network A to which it has canceled the subscription.